Подскажите: в Eclipse необходимо открыть проект сделанный в IDEA
Without access to IntelliJ to export and convert the project, try the following.
In STS or Eclipse create an empty project first, then, select File -> Import and choose General -> File System. In the resulting dialog box, select the root folder of the IntelliJ project as source and the empty project as the destination.
For unit tests, add the test folder as a source folder to the build path (right-click on the folder, select Build Path -> Use as Source Folder).
The projects I import this way run without any further modifications, including the tests.